Tags: til

29

sparkline

Thursday, May 16th, 2019

TIL (Today I learned) - Manuel Matuzović

At Clearleft, we’re always saying “Everything is a tiny lesson!”, so I love, love, love this bit of Manuel’s website where notes down short code snippets of little things he learns.

Saturday, February 16th, 2019

Sunday, September 23rd, 2018

Service workers in Samsung Internet browser

I was getting reports of some odd behaviour with the service worker on thesession.org, the Irish music website I run. Someone emailed me to say that they kept getting the offline page, even when their internet connection was perfectly fine and the site was up and running.

They didn’t mind answering my pestering follow-on questions to isolate the problem. They told me that they were using the Samsung Internet browser on Android. After a little searching, I found this message on a Github thread about using waitUntil. It’s from someone who works on the Samsung Internet team:

Sadly, the asynchronos waitUntil() is not implemented yet in our browser. Yes, we will implement it but our release cycle is so far. So, for a long time, we might not resolve the issue.

A-ha! That explains the problem. See, here’s the pattern I was using:

  1. When someone requests a file,
  2. fetch that file from the network,
  3. create a copy of the file and cache it,
  4. return the contents.

Step 1 is the event listener:

// 1. When someone requests a file
addEventListener('fetch', fetchEvent => {
  let request = fetchEvent.request;
  fetchEvent.respondWith(

Steps 2, 3, and 4 are inside that respondWith:

// 2. fetch that file from the network
fetch(request)
.then( responseFromFetch => {
  // 3. create a copy of the file and cache it
  let copy = responseFromFetch.clone();
  caches.open(cacheName)
  .then( cache => {
    cache.put(request, copy);
  })
  // 4. return the contents.
  return responseFromFetch;
})

Step 4 might well complete while step 3 is still running (remember, everything in a service worker script is asynchronous so even though I’ve written out the steps sequentially, you never know what order the steps will finish in). That’s why I’m wrapping that third step inside fetchEvent.waitUntil:

// 2. fetch that file from the network
fetch(request)
.then( responseFromFetch => {
  // 3. create a copy of the file and cache it
  let copy = responseFromFetch.clone();
  fetchEvent.waitUntil(
    caches.open(cacheName)
    .then( cache => {
      cache.put(request, copy);
    })
  );
  // 4. return the contents.
  return responseFromFetch;
})

If a browser (like Samsung Internet) doesn’t understand the bit where I say fetchEvent.waitUntil, then it will throw an error and execute the catch clause. That’s where I have my fifth and final step: “try looking in the cache instead, but if that fails, show the offline page”:

.catch( fetchError => {
  console.log(fetchError);
  return caches.match(request)
  .then( responseFromCache => {
    return responseFromCache || caches.match('/offline');
  });
})

Normally in this kind of situation, I’d use feature detection to check whether a browser understands a particular API method. But it’s a bit tricky to test for support for asynchronous waitUntil. That’s okay. I can use a try/catch statement instead. Here’s what my revised code looks like:

fetch(request)
.then( responseFromFetch => {
  let copy = responseFromFetch.clone();
  try {
    fetchEvent.waitUntil(
      caches.open(cacheName)
      .then( cache => {
        cache.put(request, copy);
      })
    );
  } catch (error) {
    console.log(error);
  }
  return responseFromFetch;
})

Now I’ve managed to localise the error. If a browser doesn’t understand the bit where I say fetchEvent.waitUntil, it will execute the code in the catch clause, and then carry on as usual. (I realise it’s a bit confusing that there are two different kinds of catch clauses going on here: on the outside there’s a .then()/.catch() combination; inside is a try{}/catch{} combination.)

At some point, when support for async waitUntil statements is universal, this precautionary measure won’t be needed, but for now wrapping them inside try doesn’t do any harm.

There are a few places in chapter five of Going Offline—the chapter about service worker strategies—where I show examples using async waitUntil. There’s nothing wrong with the code in those examples, but if you want to play it safe (especially while Samsung Internet doesn’t support async waitUntil), feel free to wrap those examples in try/catch statements. But I’m not going to make those changes part of the errata for the book. In this case, the issue isn’t with the code itself, but with browser support.

Monday, May 21st, 2018

Design systems and technological disruption – The Man in Blue

Almost every technological innovation over the last 300 years has had side effects which actually increase the number of opportunities for employment. The general trend is that the easier something is to do, the more demand there is for it.

Cameron looks at the historical effects of automation and applies that to design systems. The future he sees is one of increased design democratisation and participation.

This is actually something that designers have been championing for decades – inclusive design at all levels of the company, and an increase in design thinking at all stages of product development. Now that we finally have a chance of achieving that it’s not a time to be scared. It’s a time to be celebrated.

Friday, April 6th, 2018

Using Ethics In Web Design — Smashing Magazine

A remarkably practical in-depth guide to making ethical design decisions, with enjoyable diversions into the history of philosophy throughout.

Tuesday, August 29th, 2017

Problem space

Adam Wathan wrote an article recently called CSS Utility Classes and “Separation of Concerns”. In it, he documents his journey through different ways of thinking about CSS. A lot of it is really familiar.

Phase 1: “Semantic” CSS

Ah, yes! If you’ve been in the game for a while then this will be familiar to you. The days when we used to strive to keep our class names to a minimum and use names that described the content. But, as Adam points out:

My markup wasn’t concerned with styling decisions, but my CSS was very concerned with my markup structure.

Phase 2: Decoupling styles from structure

This is the work pioneered by Nicole with OOCSS, and followed later by methodologies like BEM and SMACSS.

This felt like a huge improvement to me. My markup was still “semantic” and didn’t contain any styling decisions, and now my CSS felt decoupled from my markup structure, with the added bonus of avoiding unnecessary selector specificity.

Amen!

But then Adam talks about the issues when you have two visually similar components that are semantically very different. He shows a few possible solutions and asks this excellent question:

For the project you’re working on, what would be more valuable: restyleable HTML, or reusable CSS?

For many projects reusable CSS is the goal. But not all projects. On the Code For America project, the HTML needed to be as clean as possible, even if that meant more brittle CSS.

Phase 3: Content-agnostic CSS components

Naming things is hard:

The more a component does, or the more specific a component is, the harder it is to reuse.

Adam offers some good advice on naming things for maximum reusability. It’s all good stuff, and this would be the point at which I would stop. At this point there’s a nice balance between reusability, readability, and semantic meaning.

But Adam goes further…

Phase 4: Content-agnostic components + utility classes

Okay. The occasional utility class (for alignment and clearing) can be very handy. This is definitely the point to stop though, right?

Phase 5: Utility-first CSS

Oh God, no!

Once this clicked for me, it wasn’t long before I had built out a whole suite of utility classes for common visual tweaks I needed, things like:

  • Text sizes, colors, and weights
  • Border colors, widths, and positions
  • Background colors
  • Flexbox utilities
  • Padding and margin helpers

If one drink feels good, then ten drinks must be better, right?

At this point there is no benefit to even having an external stylesheet. You may as well use inline styles. Ah, but Adam has anticipated this and counters with this difference between inline styles and having utility classes for everything:

You can’t just pick any value want; you have to choose from a curated list.

Right. But that isn’t a technical solution, it’s a cultural one. You could just as easily have a curated list of allowed inline style properties and values. If you are in an environment where people won’t simply create a new utility class every time they want to style something, then you are also in an environment where people won’t create new inline style combinations every time they want to style something.

I think Adam has hit on something important here, but it’s not about utility classes. His suggestion of “utility-first CSS” will only work if the vocabulary is strictly adhered to. For that to work, everyone touching the code needs to understand the system and respect the boundaries of it. That understanding and respect is far, far more important than any particular way of structuring HTML and CSS. No technical solution can replace that sort of agreement …not even slapping !important on every declaration to make them immutable.

I very much appreciate the efforts that people have put into coming up with great naming systems and methodologies, even the ones I don’t necessarily agree with. They’re all aiming to make that overlap of HTML and CSS less painful. But the really hard problem is where people overlap.

Tuesday, March 21st, 2017

Lisbon Azulejos

When I was in Porto a few weeks back, I took lots of pictures of the beautiful tiles. They reminded me of the ubiquitous repeating background images that were so popular on the early web. I was thinking about abstracting them into a collection of reusable patterns but now it looks like I’ve been beaten to it!

Wednesday, March 1st, 2017

Mood boards in a content-first design process — Thomas Byttebier

How style tiles can work great in combination with content prototypes:

Surprisingly, it helps clients understand the HTML content prototype better. They now clearly see the difference and the relationship between content and design. In general it helps me explain the content-first process better and it helps them make more sense of it.

Friday, September 30th, 2016

the new code – Even Stevens: Using Round and Space in Repeated Background Images

See, when I first heard about background-repeat: round; I thought it was something to do with making things circular. But no, it’s about tiling a background image so that nothing gets cut off. The amount of tiling required is rounded to the nearest whole number.

Now I get it.

Friday, July 24th, 2015

Meet Walter Pitts, the Homeless Genius Who Revolutionized Artificial Intelligence

The fascinating story of logic, learning, and the origins of electronic computing. Russell, Shannon, Turing, Wiener, Von Neumann …they’re all in there, woven around the tragic figure of Walter Pitts.

It is a sad and beautiful world.

Thanks to their work, there was a moment in history when neuroscience, psychiatry, computer science, mathematical logic, and artificial intelligence were all one thing, following an idea first glimpsed by Leibniz—that man, machine, number, and mind all use information as a universal currency. What appeared on the surface to be very different ingredients of the world—hunks of metal, lumps of gray matter, scratches of ink on a page—were profoundly interchangeable.

Wednesday, July 23rd, 2014

The Pattern Library

Literally a library of patterns: y’know, for tiling background images. Old school!

Sunday, June 17th, 2012

Welcome to History Mesh

This is rather wonderful: a DevFort project for navigating interweaving strands of history, James Burke style.

Tuesday, March 27th, 2012

A List Apart: Articles: Style Tiles and How They Work

Samantha does an excellent job of explaining how useful style tiles can be for visual design and iteration.

Wednesday, March 21st, 2012

maps.stamen.com

Beautiful new map tiles from Stamen for use with OpenStreetMap data. The “watercolor” tiles are particularly pretty.

Friday, March 16th, 2012

Style Tiles

Samantha put together this handy one-page site to explain Style Tiles as part of her South by Southwest presentation.

Saturday, January 7th, 2012

This is Brighton on Vimeo

A lovely timelapse tilt-shift video of Brighton.

Saturday, August 20th, 2011

agile approach | The Anatomy of a Design Decision: Examiner’s 2012 Campaign Site

Samantha gives the rundown of a hands-on use of Style Tiles.

Tuesday, April 26th, 2011

Samantha Warren’s Web Design Blog | Design ~ Web Typography ~ Inspiration

An excellent design technique from Samantha that allows you to nail down a visual vocabulary without using something as wishy-washy as a mood board or as rigid as a fully-blown comp. Brilliant!

The style tile is not a literal translation of what the website is going to be, but a starting point for the designer and the client to have a conversation and establish a common visual language.

Thursday, April 7th, 2011

The Cicada Principle and Why It Matters to Web Designers » HTML & CSS, Layout » Design Festival

A lovely bit of experimentation with prime numbers and multiple background images.

Tuesday, July 13th, 2010

flickr shapetiles / july 2010

Aaron's lovely visualisation of Flickr's shapetiles.